Stories tagged solar flare
Aurora mystery comes to light
in Earth and Space Science, Physical Science, Energy Transformations, and Forces of Nature
Northern Lights over Minneapolis: Aurora borealis dance over Lake Harriet, November 6, 2004
Courtesy Mark RyanMany years ago, three friends and I were heading home from a road trip to western Canada. It was about 2:30 in the morning, and I was driving while everyone else was sleeping. I was probably half-asleep myself. But as we chugged along Highway 2 near the outskirts of Bemidji, Minnesota, something in the upper corner of the windshield caught my eye. When I looked up, the sight was so spectacular I immediately pulled over and woke everyone up to see it. My friends were none too happy as I coaxed them out of the van into the cold northern Minnesota night.
Above us, the night sky was alive with the most incredible display of the Northern Lights I have ever witnessed. Bright, vibrant fingers of yellow, blue, red, and green light spread out from a point overhead, like a brilliant hand reaching down from the black sky. I’ve never seen colors like that since. The display was something I’ll never forget and it’s hard to convey how beautiful it actually was, but let me just say my friends soon discarded any thoughts of pummeling me with their fists.
Now, scientists have figured out the mystery behind the phenomenon. According to a new study published in the journal Science, the catalyst of the aurora borealis (and their southern counterpart aurora australis) takes place way out in space about 80,000 miles from Earth during an event called magnetic reconnection.
"Our data show clearly and for the first time that magnetic reconnection is the trigger," said Vassilis Angelopoulos, the project’s principal investigator. "Reconnection results in a slingshot acceleration of waves and plasma along magnetic field lines, lighting up the aurora underneath even before the near-Earth space has had a chance to respond."
The data was gathered by five strategically positioned satellites (a NASA mission known as THEMIS) and compared with that from ground-based detectors.
The process actually begins on the Sun. Turbulent activity on its surface sends out massive energy bursts via the solar wind that interact with the Earth’s magnetic fields and cause all sorts of havoc with our power grids and communication networks. They also create wonderful auroras. But these massive solar outbursts are only occasional, occurring maybe 10 times a year. More frequently – about every three or four hours - the geomagnetic fields are bombarded by substorms; smaller energy bursts that also create auroras. But don’t let the diminutive name deceive you. The energy generated by each substorm is huge, anywhere between one million to two million amps over one or two hours. The THEMIS project determined that, during substorms, the Earth’s magnetic field lines are stretched out like rubber bands building up tremendous amounts of energy before suddenly snapping and flinging charged particles back toward the Earth’s poles. The results are the dancing auroras seen in the northern and southern regions.
Magnetic reconnection is common throughout the known Universe and has been suspected by many as the trigger of auroras. For three decades, though, a competing theory argued the auroras were triggered much closer to Earth, by the disruption (or short-circuit) of charged ions interacting with the magnetic field.
But the new data seems to show otherwise. During a substorm studied in February, the satellites’ data showed the magnetic reconnection occurred first, followed soon after by an aurora display. Only after the display was the short-circuit observed.
Looks like the 30-year debate may be over.
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Coronal Mass Ejection: View of solar event taken in ultraviolet light by the SOHO spacecraft.
Courtesy NASACheck out the first footage of a gigantic “tsunami” captured plowing through our Sun’s atmosphere. The event was triggered by some sort of explosion on the Sun such as a solar flare or coronal mass ejection (CME). The outward-spreading wave spanned the nearly one million kilometers (600,000 miles) of the solar disk in just half an hour. But it’s the amount of energy released that is truly mind-boggling. According to one of the researchers, these explosions release “about two billion times the annual world energy consumption in just a fraction of a second.”
11 yearsun spot cycle: source; global warming art via wikipedia
Look out for sunspot 930.
If you study the graph of sunpot activity you will note they spike every 11 years.(learn more in this previous post) The last real bad one was July 14, 2000. It was rated about X6. The next peak will be around 2011. Even though 2006 is supposed to be the low point between peaks, we just got clobbered by an X9 burst of x-rays. I think it knocked out one of the sun monitoring satellites.
NOTE: The Solar X-ray Imager onboard NOAA's GOES-13 satellite is experiencing an anomaly possibly related to the X9-flare of Dec. 5th. NOAA and NASA staff are investigating. Meanwhile, coronal hole updates are suspended.
You can see a live update on proton radiation intensity here. The Dec 5 blast was not pointed toward Earth but the sunspot is swinging our way and the forcast for another X-class blast of x-rays is 50% for the next 48 hours.
Look for more news at Spaceweather.com.
Update: Here is a photo of the Dec 5 X9 class solar flare.
Fairwell sunspot 930: Credit: SOHO/MDI
Farewell Sunspot 930 (Dec 17)
GOODBYE... and thanks for the X-flares. Sunspot 930 announced itself on Dec. 5th with one of the strongest flares in years--an X9, followed by an X6 on Dec. 6th, an X3 on Dec. 13th and an X1 on Dec. 14th. Not bad for solar minimum! SpaceWeather.com
Want to see these flares in motion?
Dec. 5, 2006 X9 flare
Dec. 7, 2006 X6.5 flare
Dec 13, 2006 X3.4 flare
Dec. 14, 2006 X1 flare
Sept. 5, 2005 X17 flare Lucky this one wasn't pointed our way.
Sunspot 930 visible for about 12 days.
This leads me to believe the sun rotates on its axis about every 25 days. Since we are also going around the sun, exact figuring gets complicated, Read more about solar rotation here.
Aurora watch: Photo by Craig M. Groshek, via Wikipedia
Here it comes
Sunspot 904 erupted yesterday, Aug.16. A lot of astronomers were watching as it happened. See pictures 1, 2, 3, 4, 5.
Aurora watch alert
A coronal mass ejection (CME, movie) is heading toward Earth and could spark a geomagnetic storm when it arrives on August 18th or 19th. The cloud was hurled into space yesterday by a C3-class explosion in the magnetic field of sunspot 904. Sky watchers, prepare for auroras.
Watch for Northern Lights Friday and Saturday night.
Source; SpaceWeather
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